JPH10113804A - U shaft machining spindle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adopt a clamping mechanism which is in good balance and of rational structure. SOLUTION: A clamping mechanism 30 of a tool 11 is provided in a tool spindle 5, the center of oscillation of which is set on the axis of the spindle. The clamping mechanism is made up of a clamp sleeve 35 which travels back and forth on the axis of the tool spindle 5, and a collect ring 39 which is fitted on the clamp sleeve 35 and which radically expands or contracts as the clamp sleeve 35 is moved back and forth, and which can be engagingly locked to over the cylindrical part 6 of the tool spindle 5, and the base end part 13 of the tool 11. Further, the clamp sleeve 35 is connected to a slide clamp 31 in the rear to be moved integrally with the slide clamp, in the slide clamp 31, a cam mechanism which travels back and forth by rotatably operating a clamp shaft 53, is formed of an eccentric shaft 54 of the rectangularly penetrated clamp shaft 53, and a clamp pin 56 loaded from the rear of the slide clamp 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a U-axis machining spindle for performing a cutting process by moving a tool mounted on a tip end in a direction (U-axis direction) orthogonal to an axis. The present invention relates to an improvement in a clamp mechanism of a tool provided on a machining spindle.

[0002]

2. Description of the Related Art In the above-mentioned U-axis machining spindle, the applicant has provided a seesaw member having a swing center set on the axis of the spindle in the spindle, and provided a tool clamping mechanism at a front end thereof. At the rear end, a swing means for tilting the seesaw member at a predetermined angle from the axis of the spindle is provided, and by tilting the seesaw member by the swing means,
An invention is provided in which a tool clamped at a front end is inclined to obtain a moving amount of the tool in a U-axis direction.

On the other hand, as a clamp mechanism for mounting a tool on a turret or the like, a clamp mechanism disclosed in Japanese Patent Application Laid-Open No. 5-220607 is known. That is, a plurality of collets are radially arranged in a tool receiver formed in a turret, and a clamping sleeve that radially expands or contracts the collet by axial movement is provided coaxially in the collet, When the collet is expanded by moving the tightening sleeve, the tapered surfaces provided before and after the collet are pressed against the tapered portion on the flange side of the tool and the tapered portion on the tool receiving inner surface, respectively. This is a structure in which the receiver is connected in a wedge shape. The axial movement of the tightening sleeve is achieved by screwing a tightening nut to the rear end of the tightening sleeve, providing a worm that meshes with teeth on the outer periphery of the tightening nut, and rotating the tightening nut by rotating the worm. This screw feeds the tightening sleeve in the axial direction.

[0004]

First, in a spindle for U-axis machining, it is necessary to arrange the above-mentioned seesaw member at the axis of the spindle, so that a general tool changer cannot be adopted. Accordingly, a structure or the like is adopted in which the tapered surface of the tool side surface inserted at the tip of the seesaw member is pressed and integrated with a clamp screw, and the tool is replaced by hand according to the processing mode. Therefore, in this case, it takes time and effort for replacement, the reproducibility after replacement is poor, and the processing accuracy is reduced. On the other hand, in the above-mentioned clamp mechanism, there is an advantage that a high clamping force can be obtained, but since the worm for operating the screw feed mechanism of the tightening sleeve is arranged at a position away from the axis, regardless of when the worm is provided on a turret or the like, When employed in the spindle, the balance during rotation is deteriorated, which is a factor that hinders high-speed rotation, and causes a reduction in machining accuracy. Particularly, in the case of the above-mentioned seesaw member that is oscillated, deterioration of the balance is not preferable. In addition, the number of parts increases, the structure becomes complicated, and this leads to an increase in cost.

[0005]

Therefore, the invention according to claim 1 is characterized in that, in addition to employing the above-mentioned clamping mechanism in a spindle for U-axis machining, the improvement has a simple structure with a small number of parts and balance. An object of the present invention is to provide a U-axis machining spindle that can maintain good machining accuracy, and the configuration is such that the clamp mechanism comprises: a guide member that moves back and forth on the axis of the seesaw member; Externally fitted to the member, expands and contracts in the radial direction with the forward and backward movement of the guide member, and at the time of enlargement, is constituted by a chuck member that can be locked over the seesaw member and the tool, further behind the guide member, A sliding member that moves back and forth integrally with the guide member, and an operating shaft that penetrates the sliding member at right angles through the swing center of the seesaw member; Between the slide member and is characterized in that a cam mechanism for moving the slide member back and forth by the rotation operation of the operating shaft. In addition, in addition to the object of the first aspect, the invention according to claim 2 further comprises the step of connecting the chuck member with an axis for the purpose of rationalization of the chuck member and improvement of synchronizability at the time of expansion and contraction and reliability of the clamp. A plurality of cuts provided alternately from the front and back along the direction form a tubular body whose front and rear ends are alternately continuous.
Further, in order to prevent the tool from being loosened due to rotation of the spindle after clamping, the cam mechanism may be provided at the center of the operation shaft. The slide member is configured to include an eccentric shaft that moves the slide member back and forth by an eccentric motion accompanying the rotation of the operation shaft, while providing elasticity to the eccentric shaft and stopping the front and rear movement when the clamp of the tool is completed. Regardless of this, the rotation of the operation shaft is allowed, and the eccentric shaft is allowed to perform an eccentric movement to a position after a predetermined distance from the clamp completion position.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a tip portion of a spindle 1 in a U-axis machine, FIG. 2 is a longitudinal sectional view in which the section is rotated by 90 degrees, and FIG. 3 is a sectional view taken along line AA. Is supported by a quill provided so as to be able to move back and forth in the axial direction in the main body of a U-axis machine (not shown), and is rotated by a spindle motor provided in the U-axis machine. Similarly, the U-axis machine includes a tool control motor for moving the draw bar 23 of the spindle axis back and forth in the axial direction,
A feed motor for moving the quill back and forth in the axial direction is provided, and the spindle 1 and a tool moving device described later are controlled by NC control of these motors. A cylindrical housing 3 is fixed to the front end of the hollow spindle body 2 (the right side in FIG. 1 is defined as the front, the same applies hereinafter) by bolts. The housing 3 has a hollow portion having a cross-shaped cross section formed by the bearing metals 4 and 4 mounted on both sides. The hollow portion of the hollow portion of the spindle body 2 is formed as a seesaw member. Are accommodated. The tool spindle 5 includes a cylindrical portion 6 protruding forward from the housing 3, a central flat bar-shaped shaft support portion 7,
A trapezoidal cylindrical fulcrum shaft 9, which protrudes on both sides of the shaft support 7, comprises a back swinging portion 8 extending into the spindle body 2, and tapered recesses 10, 10 of the bearing metals 4, 4.
, The fulcrum shafts 9 and 9 in the spindle 1 are inserted.
It is supported to be able to swing around. Further, the cylindrical portion 6 has a cylindrical base end portion 13 of a tool 11 having a tip 12 at a tip end.
Is inserted and integrated with the tool spindle 5 by a clamp mechanism 30 described later. An O-ring 14 and an oil seal 15 are fitted near the base end of the cylindrical portion 6, respectively.
The inside of the housing 3 is sealed. On the other hand, a pair of bottomed holes 1 parallel to the axis of the tool spindle 5
6, 16 are formed in opposite directions to each other, and each bottomed hole 16 is formed.
The headed pins 17, 17 are loosely inserted in opposite directions, and a plurality of disc springs 18, 18,... Therefore, the tool spindle 5 is moved around the axis of the spindle 1 as shown in FIG.
In the left rotation direction, ie, the direction in which the cutting resistance is applied.

The rear swinging portion 8 is bifurcated, and the tip of the bifurcation is connected by a drive pin 20 formed in a chamfered portion 19 having a two-plane width at the top and bottom.
In this connection state, the chamfered portion 19 is inclined from the axis of the spindle 1 and has the same inclination angle (about 11 degrees here).
The drive pin 20 is gripped by the drive wedge 22 having the inclined groove 21. The rear end of the drive wedge 22 is integrated with the draw bar 23 by a petal-type connecting portion 24 provided at the tip of a draw bar 23 that is movable in the axial direction in the axis of the spindle 1. Therefore, here, the drive wedge 22 can be moved back and forth by a predetermined stroke in the hollow portion of the spindle main body 2 in conjunction with the back and forth movement of the draw bar 23, and the drive pin 20 is moved in the inclined groove 21 with the back and forth movement of the drive wedge 22. As shown by a two-dot chain line in FIG. 1, the tool spindle 5 swings along an arc locus centered on the swing center O, and also swings the swing portion 8 to swing the tool spindle 5. The swing is performed with the center O as a fulcrum. Therefore, the tool 11 gripped by the cylindrical portion 6 also swings about O, and the amount of movement in the U-axis direction is obtained. In particular, here, the distance from the swing center O to the tip 12 is set to be equal to the distance from the swing center O to the center of the drive pin 20. Will get.

A clamp mechanism 30 for the tool 11 is formed in a hollow portion of the tool spindle 5. As shown in FIGS. 4 and 5, first, a slide clamp 31 as a slide member is housed in the hollow portion so as to be coaxial with the tool spindle 5 so as to be slidable forward and backward. A clamp sleeve 35 as a guide member is screwed and integrated. Tapered portions 37a and 37b each having a smaller diameter toward the rear side are formed at a large diameter portion 36 in front of the clamp sleeve 35 and a rear end portion thereof. 38 is a clamp sleeve 35
It is a stopper that is screwed into the inside and regulates the amount of screwing of the clamp sleeve 35 into the rod portion 32. The clamp sleeve 35 is provided with a collet ring 39 as a chuck member. This is because a plurality of slits 40, 4 alternately formed from the front and back along the axial direction.
., The collets 39a, 39a... Are connected alternately at the front and rear. With this structure, the collet ring 39 itself contracts against an external force that radially expands the collet ring 39. It produces a reaction force. Further, tapered portions 37 before and after the clamp sleeve 35 are provided on the inner peripheral surface of each collet 39a.
A first tapered surface 41a and a second tapered surface 41b corresponding to a and 37b are respectively formed, while projections 42 and 43 are respectively formed on the outer peripheral surface before and after the projections 42 and 4 respectively.
The three opposing surfaces are formed on a third tapered surface 42a and a fourth tapered surface 43a having opposite directions (a smaller diameter in the forward direction from the projection 42 and a smaller diameter in the rearward direction from the projection 43). I have. Behind the collet ring 39, there is a mortar-shaped tapered portion 45 penetrated by the rod portion 32, and a forked portion 46, 46 sandwiching the intermediate portion 33 of the slide clamp 31 having a two-sided width is provided behind the collet ring 39. The formed return guide 44 is arranged. The return guide 44 is provided inside the shaft portion 34 at the rear of the slide clamp 31, and the compression spring 4 is in contact with the forked portions 46, 46.
7, 47 urges the tapered portion 45 forward.
Is pressed against a fifth tapered surface 43b formed at the rear end of the projection 43 of the collet ring 39. Furthermore, the inner surface 6a of the cylindrical portion 6 of the tool spindle 5 and the base end 1 of the tool 11
The outer surface 13a of the base 3 is formed in a gently tapered shape having a small diameter toward the rear, and is in close contact with each other when the tool 11 is mounted, and the inner surface of the base end portion 13 has a smaller diameter of the inlet than the inside. Thus, a tapered portion 48 that matches the third tapered surface 42a of the projection 42 of the collet ring 39 is formed at the boundary. A protruding ridge 49 having an inner diameter equal to the diameter of the inlet of the base end portion 13 is provided around the inner surface of the cylindrical portion 6 of the tool spindle 5, and the rear surface is formed by a fourth tapered surface of the projection 43 of the collet ring 39. Tapered portion 50 that matches 43a
Is formed.

On the other hand, the intermediate portion 33 of the slide clamp 31
In the forked portions 46, 46 of the return guide 44 sandwiching the intermediate portion 33, through holes 51, 52, 52 are respectively formed, and these through holes are orthogonal to the axis of the spindle 1 and swing. A clamp shaft 53 having both ends exposed from the fulcrum shaft 9 of the tool spindle 5 passes through the moving center O. An eccentric shaft 54 is formed in a portion of the clamp shaft 53 orthogonal to the spindle axis, and the return guide 44
The eccentric shaft 54 does not interfere with the oblong through holes 52, 52 of the forked portion 46 regardless of the front and rear positions of the fork. But middle part 3
3, a position between a front end 51 a of the through hole 51 and a tip of a clamp pin 56 inserted from the rear into the axis of the shaft portion 34 of the slide clamp 31 and protruding into the through hole 51. Accordingly, a cam mechanism in which the slide clamp 31 slides back and forth by the eccentric movement of the eccentric shaft 54 accompanying the rotation of the clamp shaft 53 is configured. 5
Reference numeral 5 denotes a set screw screwed behind the slide clamp 31 to prevent the clamp pin 56 from coming off.

In the spindle 1 configured as described above, since the tool spindle 5 has a seesaw structure in which the fulcrum shafts 9 are pivotally supported, the draw bar 23 is moved in the axial direction by the NC control of the tool control motor. As described above, the tool 11 swings along with the tool spindle 5 along an arc locus about the swing center O as described above. That is, when the draw bar 23 is retracted, the drive pin 20 moves downward as shown in FIG. 1 and the tool 11 moves upward at the same angle, thereby obtaining the amount of movement from the axis to the U-axis direction. Conversely, when the draw bar 23 is advanced, the drive pin 20 moves upward, and the tool 11 moves downward at the same angle, so that the amount of movement in the opposite direction is obtained.

When the tool 11 is mounted on the tool spindle 5, the hexagonal hole 5 at the exposed end of the clamp shaft 53 is provided.
Inserting a hexagon wrench or the like into 3a and rotating it half a turn (180 ° rotation) from a position above the center line in FIG.
The slide clamp 31 integrated with the eccentric shaft 54 by the through hole 51 and the clamp pin 56 moves axially forward according to the eccentric motion of the eccentric shaft 54 by 180 °. At this time, the integral clamp sleeve 35 also advances through the rod portion 32. The collet ring 39, which is externally mounted on the clamp sleeve 35, includes a projection 49 on the inner surface of the cylindrical portion 6 of the tool spindle 5 and a projection 43 on the rear end.
When the large-diameter portion 36 of the clamp sleeve 35 passes the front end of the collet ring 39, the rear end of the clamp sleeve 35 is attached to the front by compression springs 47, 47 together with its own contracting force. Return guide 44 to be energized
Is reduced by being guided by the tapered portion 45. Therefore, the cylindrical part 6
Between the collet ring 39 and the base end 1 of the tool 11
3 is formed (below the center line in FIG. 4). Next, when the base end portion 13 of the tool 11 is inserted into the cylindrical portion 6 and the clamp shaft 53 is further rotated half a turn from the lower position in FIG. 31 is retracted, and the clamp sleeve 35 is retracted. Accordingly, the tapered portion 37b on the rear end outer peripheral surface of the clamp sleeve 35 abuts on the second tapered surface 41b on the rear end inner peripheral surface of the collet ring 39, and the tapered portion 37a of the large diameter portion 36 is formed on the inner periphery of the collet ring 39. One taper surface 41
a, the collet ring 39 is expanded. At this time, the return guide 44 urged forward prevents the collet ring 39 from retreating. The front end of the collet ring 39 is connected to the large diameter portion 36 of the clamp sleeve 35.
, The third tapered surface 42a of the projection 42 of the collet ring 39 engages with the tapered portion 48 of the inner peripheral surface of the base end portion 13 of the tool 11 to draw the base end portion 13 and press it. At the same time, also at the rear end, the fourth tapered surface 43a of the projection 43 engages with and presses the tapered portion 50 of the ridge 49 on the inner surface of the cylindrical portion 6. Therefore, the collet ring 39 expanded by the engagement between the front and rear tapers is formed into the cylindrical portion 6 of the tool spindle 5 and the base end 13 of the tool 11.
Are connected in a wedge shape (the upper side of the center line in FIG. 4).
To remove the tool 11, if the slide clamp 31 is advanced again by the half rotation of the clamp shaft 53, the collet ring 39 contracts and the front and rear projections 42 and 43 respectively move to the base end 13 as described above. Then, the clamp sleeve 35 moves forward and the bottom of the proximal end portion 13 is pushed forward, and the clamp sleeve 35 is forcibly released from the mounted state.

As described above, in the present embodiment, the use of the clamp mechanism 30 in the U-axis processing machine facilitates the exchange of tools, and increases the clamping force. Also, a cam mechanism is adopted on the axis of the tool spindle 5 and the clamp shaft 53 for operating the same is pivoted to the center of rotation O.
, The clamp mechanism 30 can be compactly configured in the spindle 1 without losing the balance of the spindle 1, and the spindle 1 can be prevented from being enlarged. Therefore, the spindle 1 can be rotated at a high speed, which leads to an improvement in processing accuracy. In addition, since the collet ring 39 is an integrated type in which each collet is alternately connected back and forth by a slit 40, the collet ring 39 itself can be given elasticity to the contraction side, and a ring spring or the like is not required. It is possible to eliminate variation in each collet when expanding and contracting, and to secure preferable synchronizability. The rotation operation of the clamp shaft 53 for expanding and contracting the collet ring 39 is not limited to the manual operation using the hexagonal wrench, and a wrench drive mechanism for rotating the hexagonal wrench by hydraulic pressure, a servomotor, or the like is separately provided. For example, if the tool is used together with a turntable or the like capable of storing a plurality of tools, the tools can be easily changed automatically. The cam mechanism for moving the slide clamp 31 back and forth is not limited to the eccentric shaft 54 and the crankpin 56 penetrating the through hole 51, and can be designed and modified as appropriate. For example, a cam or cam having an appropriate contour curve at the center of the clamp shaft Provide a groove and slide clamp 3
The slide clamp 31 may be moved forward and backward by the rotation of the cam caused by the rotation of the clamp shaft 53 such that the clamp pin 56 and the like are constantly pressed against the cam by a biasing means separately provided on the cam 1.

In the above-described embodiment, the clamp shaft 53 is rotated by approximately 180 ° when the tool 11 is clamped.
May cause the clamp shaft 53 to be loosened. Therefore, a safety mechanism capable of effectively preventing such loosening will be described below. As shown in FIG. 6, in the clamp shaft 53, the eccentric shaft 54a is longer than that of FIG. 2 (by the way, 10 mm in FIG. 2, and 40 mm in FIG. 6) to provide elasticity in the radial direction. A pair of grooves 57, 57 are formed in the outer circumference of both ends along the circumferential direction, slightly longer than a half circumference. On the other hand, stopper pins 58, 58 to be inserted into the grooves 57, 57 are mounted on the bearing metals 4, 4 that support the clamp shaft 53, respectively. At the rotation position of the clamp shaft 53 in the unclamped state, the stopper pins 58 and 58 respectively have grooves 57 as shown in FIG.
Is located at the start end 57a. Therefore, in this embodiment, when the clamp shaft 53 is rotated in the direction of the arrow from the unclamped state of FIG. 7A, the eccentric shaft 54a eccentrically moves backward as described above, 31, clamp sleeve 35
Retreat. Then, when the tool 11 is rotated by approximately 180 °, that is, at the position of the eccentric shaft 54a shown by a two-dot chain line in FIG. 7B, the clamping of the tool 11 is completed. Clamp pin 56
Even if the eccentric shaft 54a does not further retract, the eccentric shaft 54a slightly flexes forward due to elasticity and allows the rotation of the clamp shaft 53,
The stopper pins 58, 58 are connected to the ends 57b of the grooves 57, 57,
Upon reaching the position 57b, the rotation of the clamp shaft 53 stops. Therefore, as shown by the solid line in FIG.
It can be rotated from the unclamped position to an angle of 180 ° + α. As a result, the eccentric shaft 54a rotates beyond the clamp position to a position where it is difficult to return, so that the clamp shaft 53 is effectively prevented from loosening due to the rotation of the spindle 1 and the tool 11 can be securely clamped. It can be maintained. The length and diameter of the eccentric shaft 54a may be appropriately changed in order to obtain desired elasticity.

[0014]

As described above, according to the first aspect of the present invention, it is possible to suitably employ a clamping mechanism capable of obtaining a high clamping force for a U-axis machining spindle using a seesaw member. Therefore, the labor and time for replacement can be reduced, the reproducibility after replacement is favorable, and the processing accuracy is good. In particular, the movement control of the slide member in the clamp mechanism is performed by the operation shaft and the cam mechanism passing through the swing center of the seesaw member, thereby affecting the balance of the seesaw member that feeds the tool in the U-axis direction. It does not hinder high-speed rotation of the spindle or maintenance of machining accuracy. In addition, the structure becomes simple with a small number of parts, and the cost increase can be suppressed. According to the second aspect of the present invention, if the chuck member is formed into a tubular body whose front and rear ends are alternately continuous by a plurality of cuts provided alternately from front and rear along the axial direction, Elasticity in the reduction direction can be given to itself,
As compared with the case where the collet is intermittently arranged, an urging means such as a ring spring is not required. In addition, the continuous tubular body improves the synchronism during expansion and contraction, and also ensures the reliability of the operation during clamping and unclamping. Further, according to the third aspect of the present invention, by providing elasticity to the eccentric shaft constituting the cam mechanism, it is possible to perform eccentric movement of the eccentric shaft up to a position beyond the clamp completion position by a predetermined amount, The loosening of the operating shaft due to the rotation of the spindle, that is, the loosening of the tool, can be effectively prevented, and the clamped state can be suitably maintained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tip end of a spindle.

FIG. 2 is a vertical cross-sectional view of a tip end of a spindle moved 90 degrees from the cross section of FIG.

FIG. 3 is an enlarged sectional view taken along line AA.

FIG. 4 is an explanatory diagram of a clamp mechanism.

FIG. 5 is an exploded view of the clamp mechanism.

FIG. 6 is an explanatory diagram of a safety mechanism.

FIG. 7A is an explanatory view showing an eccentric motion of an eccentric shaft in a safety mechanism. (B) It is explanatory drawing which shows the eccentric motion of the eccentric shaft in a safety mechanism.

[Explanation of symbols]

1. Spindle, 2. Spindle body, 5. Tool spindle, 11 Tool, 30 Clamp mechanism, 31 Slide clamp, 35 Clamp sleeve, 39 Collet ring, 41a No. One tapered surface, 41b, second tapered surface, 42, 43, projection, 4
2a... Third tapered surface, 43a... Fourth tapered surface, 44
··· Return guide, 53 ·· Clamp shaft, 54 ·· Eccentric shaft, 56 ·· Clamp pin.

Claims (3)

[Claims] 1. A seesaw member having a swing center set on an axis of a spindle is provided in a spindle, and a clamp mechanism capable of mounting a tool on the axis of the seesaw member is provided at a front end thereof, while a rear end is provided. A U-axis machining spindle provided with a rocking means for tilting the seesaw member at a predetermined angle from the axis of the spindle, a guide member for moving the clamp mechanism back and forth on the axis in the seesaw member And, it is fitted around the guide member, and expands and contracts in the radial direction with the forward and backward movement of the guide member,
It comprises a seesaw member and a chuck member which can be locked over a tool when enlarging, and further includes a slide member which moves back and forth integrally with the guide member behind the guide member, and swings the seesaw member. An operation shaft that passes through the slide member at right angles through the center is provided, and a cam mechanism that moves the slide member back and forth by rotating the operation shaft is provided between the operation shaft and the slide member. Spindle for U-axis machining. 2. The spindle for U-axis machining according to claim 1, wherein the chuck member is a cylindrical body alternately continuous at front and rear ends by a plurality of cuts provided alternately from front and rear along the axial direction. . 3. The eccentric shaft, which is provided at the center of the operating shaft and moves the slide member back and forth by eccentric movement accompanying rotation of the operating shaft, while imparting elasticity to the eccentric shaft. Then, irrespective of the slide member that has stopped moving back and forth due to the completion of the clamping of the tool, the rotation of the operation shaft is allowed, and the eccentric shaft can perform an eccentric movement to a position beyond a predetermined amount of the clamping completion position by the eccentric shaft. The U-axis machining spindle according to claim 1 or 2, wherein